1. FIELD OF THE INVENTION
The present invention generally relates to pliers used to grasp and deform articles such as metal clasps. More specifically, this invention relates to archery bow pliers adapted for both attaching and removing a split nock ring from a bow string.
2. DESCRIPTION OF THE PRIOR ART
Split nock rings are commonly used by archers to accurately locate the rearward end of an arrow on the bow string. The rearward end of the arrow has a diametral groove, referred to as a nock, which is positioned below the split nock ring on the bow string so as to accurately and repeatably locate the arrow on the bow string. By positioning the arrow accurately with respect to the bow string, and thus also with respect to the bow, the arrow's trajectory can be better predicted, thereby providing improved precision of the archer's aim.
Typically, the split nock ring is annular-shaped with an axial length of approximately 1/8 inches. The split nock ring is formed of a resilient metal, such as brass, having a thickness of approximately 1/32 inches. The split ring is generally U-shaped with a longitudinal cleft which forms a passage or split in the side of the nock ring through which the bow string is passed when installing the nock ring on the bow string. Prior to installation, both the width of the cleft and the inner diameter of the split nock ring are approximately equal to the outer diameter of the bow string, which is typically about 1/8 inch in diameter. Once positioned on the bow string, the split nock ring is compressed on its circumference with a suitable tool to collapse its inner diameter, causing the split nock ring to crimp tightly around the bow string. The interference caused by the crimping permanently maintains the split nock ring at its installed location on the bow string until the split nock ring is forcibly removed.
Split nock rings typically need to be replaced or relocated on occasion, requiring that the cleft in the nock ring be reopened to allow removal of the nock ring from the bow string. The process of removing the nock ring is complicated in that removal must be accomplished without damaging the bow string. Where the nock ring is merely being relocated, minimal harm to the split nock ring is also preferable to allow the split nock ring to be reused.
Bow strings typically consist of a number of tightly-wound strands which are often protected with a nylon thread wrapped around the bow string in the area where the split nock ring, and thus the arrow, is positioned. This protective wrap is particularly vulnerable to damage while the split nock ring is being removed. Common methods of removing split nock rings, such as with the use of conventional pliers or other commonly available tools capable of prying the cleft apart, are undesirable for this reason. The user cannot adequately control the tool while simultaneously positioning it with respect to the bow string. Consequently, many attempts are often necessary to remove the split nock ring, and then such attempts often do not entirely avoid damaging either the bow string or the split nock ring.
Specially adapted pliers for crimping split nock ring on bow strings are well known in the art. Typically, split nock ring crimping pliers are formed with two semi-circular recesses, one on each half of the plier jaws, which are sized to define the crimped diameter of the split nock ring. The split nock ring can then be loaded into the recesses, positioned around the bow string by passing the bow string through the cleft, and then crimped by bringing the two halves of the pliers together.
Similarly, such special adaptations are commonly devised for pliers which are intended to be used as a crimping tool. Examples of known modifications made to pliers to facilitate a crimping action can be seen in U.S. Pat. Nos. 2,562,097 to Heuer, 2,254,410 to Burns, 1,948,865 to Miller et al, and 1,067,876 to Merritt. Each represents an approach to accomplishing a particular crimping operation. However, all of these tools, including the conventional split nock ring crimping pliers known to the prior art, are adapted for crimping and are not intended or even suggested to be useful for splitting a ring open after being crimped closed. Again, removal of the split nock rings from bow strings is typically achieved by such awkward tools as common pliers or prying tools.
Therefore, a device is needed which can remove a split nock ring from a bow string without damaging the bowstring and without excessively deforming the split nock ring such that it can be reused.